The present invention is related to flexible wound dressings and more specifically to flexible wound dressings that have therapeutic qualities.
Controlling bleeding, fighting infection and improving wound healing are major medical issues. Methods to control bleeding and repairing wounds have existed for many years. Traditional surgical hemostatic techniques have included applying pressure, cauterizing, and suturing. Over the past 20 years, a number of hemostatic agents and tissue sealants have been developed and are currently used in various surgical disciplines. The hemostatic agents act to stop bleeding either mechanically or by augmenting the coagulation cascade, whereas tissue sealants are products that bind to and close defects in tissue. Currently there are five major classes of the hemostatic agents and tissue sealants for surgical use, including fibrin glue, bovine collagen and thrombin, cyanoacrylate, polyethylene glycol polymer, and albumin crosslinked with glutaraldehyde. These hemostatic agents are mainly composed of allogeneic or hetreallogeneic proteins.
Recently, chitosan based hemostatic dressings have been shown to control aggressive hemorrhages from severe external injuries. The chitosan dressing acts to control severe hemorrhagic bleeding by first sealing the wound site followed by promotion of local blood coagulation. An external form of this chitosan wound dressing was cleared by the Food and Drug Administration for external temporary control of severely bleeding wounds intended for emergency use.
However, in some applications, for example, a narrow entry wound, current chitosan and nonchitosan based wound dressing are not effective at providing hemostasis, fighting infection and/or promoting wound healing. Currently available dressings are often too stiff and too rigid to fit in a narrow space or they are too flexible and porous to efficiently promote hemostasis. Powder based hemostatic products also have limited effectiveness as they are difficult to apply to bleeding sites through narrow wound entries.